Some CEOs unwind during the weekend by playing golf. George Hatsopoulos preferred to hole up in his home study, fogged with pipe smoke, and elaborate his theories on thermodynamics or economic policy.

A Greek immigrant who settled in the Boston area, he founded a Fortune 500 company, Thermo Electron Corp., and ran it for 43 years. He co-wrote a thermodynamics textbook and lectured at the Massachusetts Institute of Technology. Though self-taught in economics, he wrote economic-research papers with professionals including Paul...